Gait

Question 1

external appliance worn to restrict or assist motion or to transfer load from one area to another

Answer 1

orthosis
plural = orthoses

Question 2

a replacement of all or part of the leg or arm

Answer 2

prosthesis
plural = prostheses

Question 3

traditional gait phases in order:
Rancho terminology in order:

Answer 3

heel strike, foot flat, midstance, heel off, toe off, acceleration, mid swing, deceleration

initial contact, loading response, midstance, terminal stance, pre swing, initial swing, midswing, terminal swing

Question 4

stance phase = ___%
swing phase = ____ %

Answer 4

60%
40%

Question 5

phases of gait cycle Rancho terminology

Answer 5

initial contact 0%
loading response 0-10%
midstance 10-30%
terminal stance 30-50%
pre swing 50-60%
____________________________________________
initial swing 60-73%
midswing 73-87%
terminal swing 87-100%

Question 6

which phases of gait in the stance phase are in single support? double support?

Answer 6

single: mid stance & terminal stance (40%)
double: initial contact, loading response, pre swing (20%)

Question 7

rate of linear forward motion of the body
measured in?

Answer 7

velocity
(m/sec)

Question 8

number of steps taken per unit of time
measured in?

Answer 8

cadence
(steps/min)

Question 9

heel strike to ipsilateral heel strike

Answer 9

stride length

Question 10

heel strike to contralateral heel strike

Answer 10

step length

Question 11

width of base of support

Answer 11

step width

Question 12

what is considered the 6th vital sign?

Answer 12

walking speed

Question 13

what gait speed is considered a community ambulator?

Answer 13

0.8 m/sec or greater

Question 14

1 stride = _____ = ______

Answer 14

1 gait cycle = 2 steps

Question 15

produces external torque/moment:
– examples:

Answer 15

external forces
– ground reaction force, gravity/air resistance/friction

Question 16

Internal forces usually respond to what type of external factor?

Answer 16

Internal forces usually respond to external torque created by the ground reaction force (GRF).

Question 17

forces applied to the body by the ground, opposing forces applied to the ground during a step

Answer 17

GRF in gait

Question 18

GRF components:

Answer 18

vertical
A-P
Med-Lat

Question 19

what direction(s) are the GRF coming from in:
– heel strike
– foot flat
– toe off

Answer 19

– vertical, A-P
– vertical
– vertical, A-P

Question 20

when does the foot exhibit M-L GRF?

Answer 20

very small amount of time in loading response

Question 21

vertical GRF:
– 2 peaks = ___% of body weight
–> F1 =
–> F3 =
– 1 valley = ____% of body weight
–> F2 =

Answer 21

– 110%
–> at weight acceptance, due to the action of body momentum
–> at terminal stance, caused by the push of ankle PFs against the floor in combination with the downward acceleration of COG
– 80%
–> at midstance, created by the rise of COG

Question 22

how do joint angles and GRFs interact?

Answer 22

moment aka torque

Question 23

potential for a force, acting a distance from the axis of rotation, to produce rotation of a segment
– units?

Answer 23

moment = torque
– Nm or kgm

Question 24

what is the equation for torque?

Answer 24

torque = force x moment arm

** moment arm = perpendicular distance between axis of rotation and line of action of the force

Question 25

what is the right hand rule?

Answer 25

the torque is in the direction along the axis of the spin angular velocity which would be produced by it -- when turning right hand counterclockwise: thumb will point outwards -- when turning right hand clockwise: thumb will point inwards

Question 26

In the stance phase of gait, weight acceptance, and single-limb support are two essential functional tasks. What primary outcome do these tasks contribute to?

Answer 26

forward progression

Question 27

In the swing phase of gait, swing limb advancement is one functional task. What is it needed for?

Answer 27

Foot clearance

Question 28

What two phase make up the first rocker? a) Loading response and terminal stance b) Initial contact & pre swing c) Mid-stance & initial contact d) Initial contact & loading reponse

Answer 28

d) Initial contact & loading reponse

Question 29

In Weight Acceptance, which three main objectives are achieved during the loading response? a) Shock absorption and impact deceleration b) Weight-bearing stability, maintain COG and preservation of progression c) Shock absorption, weight bearing stability and preservation of progression d) Impact deceleration and increase speed and maintain progression

Answer 29

c) Shock absorption, weight-bearing stability, and preservation of progression

Question 30

task 1: weight acceptance (WA): loading response objectives (3)

Answer 30

shock absorption weight bearing stability preservation of progression

Question 31

what is initial contact? what percentage of the gait cycle?

Answer 31

the moment when the foot strikes the ground 0%

Question 32

During Initial Contact, what position is the ankle held in?

Answer 32

neutral: held by pre-tibial muscles

Question 33

What is the typical position of the knee during Initial Contact? a) Full extension (5 degrees of flexion) b) Slight flexion (15 degrees) c) Fully flexed (90 degrees) d) Slight hyperextension

Answer 33

a) Full extension (5 degrees of flexion)

Question 34

What role does the hip play during Initial Contact? a) Allows for maximum extension b) Provides a position for optimal forward progression and stability c) Prevents knee flexion d) Initiates swing phase

Answer 34

b) Provides a position for optimal forward progression and stability

Question 35

What is the typical position of the hip during Initial Contact?

Answer 35

peak flexion 20 degrees

Question 36

**What is the critical event in initial contact?**

Answer 36

heel contact

Question 37

what muscle activity is needed for each external moment in initial contact? -- hip ____ moment -- knee _____ moment -- ___ moment

Answer 37

-- [flexion] hamstrings and gluteals for hip stability -- [extension] quadriceps for knee stability -- [PF] pre-tibials to counterbalance PF moment

Question 38

what is loading response? what percent of the gait cycle?

Answer 38

shock is absorbed while forward momentum is preserved. Foot flat position is achieved 0-10%

Question 39

loading response positions: -- ankle -- knee -- hip

Answer 39

-- 5 deg of PF; subtalar eversion -- 20 deg of flexion for shock absorption -- flexion 20 deg.

Question 40

at what point is the 1st rocker?

Answer 40

during loading response at the heel

Question 41

**what are the critical events during loading response? (3)**

Answer 41

- pre-tibial muscles eccentrically control PF (5 deg) - quads active to control knee flexion moment - hip extensors active for stability

Question 42

what muscle activity is needed for each external moment in loading response? -- hip _____ moment -- knee ______ moment -- ____ moment

Answer 42

-- [flexion] hamstrings and gluteals for hip stability -- [flexion] quadriceps to counterbalance flexion moment -- [PF] pre-tibials to counterbalance PF moment. Calf for stance stability

Question 43

task 2: single limb support: midstance objectives (2)

Answer 43

- progression over stationary foot - limb and trunk stability

Question 44

task 2: single limb support: terminal stance objectives (2)

Answer 44

- progression of body beyond the supporting foot - limb and trunk stability

Question 45

what is midstance? percentage of gait cycle?

Answer 45

body progresses over foot in controlled manner. contralateral limb provides momentum 10-30%

Question 46

midstance positions: -- ankle -- knee -- hip

Answer 46

-- DF controlled eccentrically -- extension -- neutral

Question 47

at what point is the 2nd rocker?

Answer 47

during LR/midstance at the ankle

Question 48

what is the critical event during midstance?

Answer 48

dorsiflexion controlled eccentrically by gastroc and soleus

Question 49

what muscle activity is needed for each external moment in midstance? -- hip ____ moment -- knee ______ moment -- ___ moment

Answer 49

-- [extension] no muscle activity -- [extension] quadriceps for stance stability -- [DF] calf (eccentrically controls) for stance stability and to counterbalance DF moment

Question 50

terminal stance positions: -- ankle -- knee -- hip

Answer 50

-- noted by heel rise (normal DF ROM 20 deg), decline in gastroc/soleus mm activity -- full extension to maximum step length -- 20 deg of apparent hyperextension for maximum step length (peak hip ext)

Question 51

what is the critical event in terminal stance?

Answer 51

trailing limb (posterior positioning)

Question 52

at what point is the 3rd rocker?

Answer 52

terminal stance at forefoot (heel off)

Question 53

what muscle activity is needed for each external moment in terminal stance? -- hip _____ moment -- knee _______ moment -- ___ moment

Answer 53

-- [extension] no muscle activity -- [extension] no muscle activity -- [DF] Large! calf to counterbalance DF moment

Question 54

task 3: swing limb advancement: pre-swing objectives (2)

Answer 54

-- position of limb for swing -- accelerate progression

Question 55

task 3: swing limb advancement: initial swing objectives (2)

Answer 55

-- foot clearance -- advancement of the limb from the trailing limb position

Question 56

task 3: swing limb advancement: mid swing objectives (2)

Answer 56

-- limb advancement -- foot clearance

Question 57

task 3: swing limb advancement: terminal swing objectives (2)

Answer 57

-- complete limb advancement -- prepare limb for stance

Question 58

what is preswing? what percentage of the gait cycle?

Answer 58

forefoot remains on the ground. knee rapidly flexes while weight is shifted to other limb 50-60%

Question 59

preswing positions: -- ankle -- knee -- hip

Answer 59

-- 2nd arc of PF (15 deg); no gastroc/soleus mm activity (no push off); 60deg great toe extension -- passive knee flexion (40 deg); prepares limb for toe clearance -- 10 deg apparent hyperextension

Question 60

what is the critical event of pre swing?

Answer 60

passive knee flexion (40 deg)

Question 61

what muscle activity is needed for each external moment in pre swing? -- hip _____ moment -- knee _______ moment -- ___ moment

Answer 61

-- [extension] hip flexors to counterbalance extension moment and initiate swing -- [flexion] no muscle activity -- [DF] Calf to counterbalance DF moment (early); pre tibials for foot clearance (late)

Question 62

Initial swing positions: -- ankle: -- knee -- hip

Answer 62

-- nearly neutral -- peak flexion for toe clearance (60 deg); peak mm activity of biceps femoris short head, sartorius, gracilis -- 15 deg flexion; peak mm activity of gracilis and sartorius

Question 63

what are the two critical events for initial swing?

Answer 63

-- peak flexion (60 deg) for toe clearance -- 15 deg. hip flexion

Question 64

what percentage of the gait cycle is initial swing?

Answer 64

60-73%

Question 65

what is midswing? what percentage of the gait cycle?

Answer 65

tibia is perpendicular to the ground 73-87% of gait cycle

Question 66

midswing positions: -- ankle -- knee -- hip

Answer 66

-- neutral to slight DF -- passive ext. cause by the momentum of hip flexion (flexion to extension) -- peak flexion 25 deg

Question 67

what is the critical event in midswing?

Answer 67

neutral to slight DF

Question 68

what is terminal swing? what percentage of the gait cycle?

Answer 68

leg reaches out to achieve step length. preparation for initial contact 87-100%

Question 69

terminal swing positions: -- ankle -- knee -- hip

Answer 69

-- neutral to prepare for heel strike -- extension to neutral (5 deg flex); ext. controlled eccentrically by the hamstrings; quads turn on in late terminal swing to prepare for WBing -- subtle retraction to 20 deg of flexion

Question 70

what is the critical event during terminal swing?

Answer 70

knee extension to neutral (5 deg flex)